<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<ul class="classes-box">
    {% for i in classes %}
        <li>
            <a href="/demo/nav/{{ i }}" {% if now_cls == i %}style="color: red"{% endif %}>
                {{ i }}
            </a>
        </li>
    {% endfor %}
</ul>
</body>
</html>